I'M NO THIEF! Elissa Drassinower says she only forgot to pay for the items she left in her son's stroller at an Upper East Side Fairway. The store says she was stealing. Photo: Ben Parker

Fairway banished an Upper East Side mom to the supermarket’s Rikers aisle after she failed to pay for a half-gallon of milk that she says she accidentally left in her stroller.

“The security guard took my photograph, told me I was banned from Fairway for life and said I was lucky she didn’t call the police,” said Elissa Drassinower, 33. “I was crying, my 20-month-old son was crying. It was humiliating.”

The stay-at-home mom insists she wasn’t shoplifting her groceries — in fact, she couldn’t lift them at all.

“My handbasket was getting so heavy, my arm was turning red. So I put the milk and a six pack of Corona under the stroller,” she said. “When I was checking out, my son, who was really cranky, started acting up, and I forgot to pay for the milk and the beer.”

When she pushed the stroller outside the East 86th Street market, the guard was waiting.

“She said she saw me put the milk and beer under the stroller. I apologized, explained what happened, said it was an honest mistake and that I fully intended to pay, but she just nodded her head and told me I was shoplifting,” the mom said.

Drassinower motioned to the $50 of groceries she had just bought and said, “If I really meant to shoplift, why would I pay for the $15 brie and the cranberry Stilton only to steal $3.49 milk?”

The guard was unconvinced.

“I’m sorry, ma’am,” she told her, according to Drassinower. “But you are banned from Fairway for life. You are not allowed to enter this store, and if you do, you’ll be arrested for trespassing.”

A team of security guards then surrounded her as though she were Ma Barker, took her photo and asked her to sign forms, she said.

“They did this all right in front of the store, making a scene,” she said. “Embarrassed, I kept asking to talk to a store manager, but they said none was on duty.”

Drassinower, who wasn’t arrested, said she was outraged and pleaded with market staff for the next few days to lift the ban — to no avail.

Fairway stands by its decision, saying she was seen putting items under her stroller and covering them with the bagged goods she had paid for.

“The woman in question was caught both on camera and by security trying to conceal and pilfer a number of items including milk, Red Bull and beer. We exercised our right to not serve her again,” said Bruce Bobbins, a spokesman for the company.

But Drassinower, who has no criminal record, said, “I threw the bags underneath my stroller and didn’t even look at what was in there.”